Targeting Antheraea pernyi silk fibroin modified dual-gene coexpressing vector enhances gene transport and promotes lung tumor suppression.

Poor systemic administration capability, a natural tendency to target CAR-positive cells, nonspecific shedding to normal organs, and poor viral persistence in tumor tissues are major hindrances to the therapeutic benefit of adenovirus (Ad) gene vectors in the clinical setting. Antheraea pernyi silk fibroin (ASF) grafted with targeted peptides was used to coat ING4-IL-24 dual-gene coexpressing adenovirus for targeted gene therapy of lung carcinoma. The dual-gene vector with a diameter of 390 nm could target and infect H460 lung tumor cells, internalize into cells, express the ING4 and IL-24 genes at a high level, effectively inhibit the proliferation of lung tumor cells, and induce their apoptosis. The in vivo treatment of H460 human lung carcinoma xenograft tumors showed that the dual-gene coexpressing vector suppressed the proliferation of lung tumor cells by downregulating the expression of Ki67 and Bcl-2, promoted apoptosis by upregulating the expression of C Caspase-3 and Bax, and blocked tumor angiogenesis by downregulating the expression of VEGF and CD31, thus exerting a multichannel tumor inhibition effect. Surface modification of Ad with targeted cationic silk fibroin is an effective way to solve the natural tendencies and in vivo instability of adenovirus vectors, and such vectors have potential for clinical application.

Advances in the antitumor mechanisms of tripartite motif-containing protein 3.

The tripartite motif-containing (TRIM) protein family has steadily become a hotspot in tumor-related research. As a member of the E3 ubiquitin ligase family, TRIM is working on many crucial biological processes, including the regulation of tumor cell proliferation, metastasis, apoptosis, and autophagy. Among the diverse TRIM superfamily members, TRIM3 operates via different mechanisms in various types of tumors. This review primarily focuses on the current state of research regarding the antitumor mechanisms of TRIM3 in different cancers. A more in-depth study of TRIM3 may provide new directions for future antitumor treatments. Our review focuses on TRIM3 proteins and cancer. We searched for relevant articles on the mechanisms by which TRIM3 affects tumorigenesis and development from 1997 to 2023 and summarized the latest progress and future directions. Triad-containing motif protein 3 (TRIM3) is an important protein, which plays a key role in the process of tumorigenesis and development. The comprehensive exploration of TRIM3 is anticipated to pave the way for future advancements in antitumor therapy, which is expected to be a new hallmark for cancer detection and a novel target for drug action. TRIM3 is poised to become a significant milestone in cancer detection and a promising focal point for drug intervention. Recent years have witnessed notable progress in research aimed at unraveling the antitumor mechanism of TRIM3, with far-reaching implications for practical tumor diagnosis, treatment protocols, efficacy evaluation, economics, and pharmaceutical utilization.

Nanoenabled Intracellular Metal Ion Homeostasis Regulation for Tumor Therapy.

Endogenous essential metal ions play an important role in many life processes, especially in tumor development and immune response. The approval of various metallodrugs for tumor therapy brings more attention to the antitumor effect of metal ions. With the deepening understanding of the regulation mechanisms of metal ion homeostasis in vivo, breaking intracellular metal ion homeostasis becomes a new means to inhibit the proliferation of tumor cells and activate antitumor immune response. Diverse nanomedicines with the loading of small molecular ion regulators or metal ions have been developed to disrupt metal ion homeostasis in tumor cells, with higher safety and efficiency than free small molecular ion regulators or metal compounds. This comprehensive review focuses on the latest progress of various intracellular metal ion homeostasis regulation-based nanomedicines in tumor therapy including calcium ion (Ca2+ ), ferrous ion (Fe2+ ), cuprous ion (Cu+ ), managanese ion (Mn2+ ), and zinc ion (Zn2+ ). The physiological functions and homeostasis regulation processes of ions are summarized to guide the design of metal ion regulation-based nanomedicines. Then the antitumor mechanisms of various ions-based nanomedicines and some efficient synergistic therapies are highlighted. Finally, the challenges and future developments of ion regulation-based antitumor therapy are also discussed, hoping to provide a reference for finding more effective metal ions and synergistic therapies.

Scoparone from Artemisia capillaris Thunb. induces apoptosis in HepG2 cells via activation of both intracellular and extracellular pathways.

Six separated compounds were identified from Artemisia capillaris Thunb., and they were 7-methoxycoumarin (1), 6,7-dimethoxycoumarin (2), 7-hydroxy-6-methoxycoumarin (3), quercetin (4), chlorogenic acid (5) and caffeic acid (6). Among them, 6,7-dimethoxycoumarin, as known as scoparone, was the most effective on scavenging ABTS free radicals (IC50 = 0.97 µΜ) and was then tested by cytotoxic activity and pro-apoptotic activity against HepG2 cells. Scoparone dose-dependently and time-dependently inhibited the cell proliferation. Furthermore, scoparone induced the expression of Bax, concurrently suppressing the expression of Bcl-2, resulting in a noteworthy elevation in the Bax/Bcl-2 ratio to up-regulate Caspase-3 activity, thus inducing cell apoptosis via the intracellular pathway. Meanwhile, scoparone promoted the expression of Fas, FasL, FADD, Caspase-8 and Caspase-3, indicating that scoparone also triggered apoptosis via the extracellular pathway. In a word, scoparone demonstrated remarkable antitumor capability to induce apoptosis of HepG2 cells through both intracellular and extracellular pathways.

Multifunctional O-phenanthroline silver(I) complexes for antitumor activity against colorectal adenocarcinoma cells and antimicrobial properties by multiple mechanisms.

A series of O-phenanthroline silver(I) complexes were synthesized and characterized by infrared (IR) spectroscopy, mass spectrometry (MS), 1H nuclear magnetic resonance (NMR) spectroscopy and single-crystal X-ray crystallography. The cytotoxicity of the silver(I) complex (P-131) was evaluated in the cancer cell lines HCT-116, HeLa, and MDA-MB-231 and the normal cell line LO2 via MTT assays. The 50% inhibition concentration (IC50) of P-131 on HCT116 cell line is 0.86 ± 0.03 µM. It is far lower than the IC50 value of cisplatin (9.08 ± 1.10 µM), the IC50 value of normal cell LO2 (76.20 ± 0.48 µM) is much higher than that of cisplatin (3.99 ± 0.74 µM), indicating that its anticancer effect is stronger than that of cisplatin, and its biological safety is greater than that of cisplatin. Furthermore, anticancer mechanistic studies showed that P-131 inhibited cell proliferation by blocking DNA synthesis and acted temporally on the nucleus in dividing HCT-116 cells. Moreover, P-131 increased intracellular reactive oxygen species (ROS) levels in a dose-dependent manner. Notably, 10 mg/kg P-131 showed better antitumor effects than oxaliplatin in an HCT116 human colorectal xenograft mouse model without inducing toxicity. Moreover, the microdilution broth method was used to evaluate the antimicrobial properties of P-131 against Pseudomonas aeruginosa and Candida albicans. A biofilm eradication study was also performed using the crystal violet method and confocal laser scanning microscopy.

Hollow Nanooxidase Enhanced Phototherapy Against Solid Tumors.

Although phototherapy has attracted extensive attention in antitumor field in recent years, its therapeutic effect is usually unsatisfactory because of the complexity and variability of the tumor microenvironment (TME). Herein, we report novel CoSn(OH)6@CoOOH hollow carriers with oxidase properties that can enhance phototherapy. Hollow CoSn(OH)6@CoOOH nanocubes (NCs) with a particle size of ∼160 nm were synthesized via a two-step process of coprecipitation and etching. These NCs can react with O2 to generate singlet oxygen without hydrogen peroxide and consume glutathione, and their hollow structure can be utilized to carry drug molecules. After loading indocyanine green (ICG) and 1,2-bis(2-(4,5-dihydro-1H-imidazol-2-yl)propan-2-yl) diazene dihydrochloride (AIPH), the resulting nanosystem (HCIA) exhibited enhanced phototherapy effects through the catalytic activity of oxidase, production of alkyl radicals, and consumption of glutathione. Cell and mouse experiments showed that HCIA combined with near-infrared laser irradiation significantly inhibited the growth of 4T1 tumors. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that PI3K-Akt and MAPK signaling pathways were highly relevant to this therapeutic system. Such hollow NCs with oxidase activity have considerable potential for the design of multifunctional drug delivery vehicles for tumor therapy.

XS-2, a novel potent dual PI3K/mTOR inhibitor, exhibits high in vitro and in vivo anti-breast cancer activity and low toxicity with the potential to inhibit the invasion and migration of triple-negative breast cancer.

Breast cancer has become the most commonly diagnosed cancer, surpassing lung cancer, with 2.26 million new breast cancers worldwide in 2020. Hence, there is an urgent need to develop effective molecularly targeted therapeutic drugs to treat breast cancer. In this paper, we designed, synthesized and screened a novel thiophene-triazine derivative, XS-2, as a potent dual PI3K/mTOR inhibitor for the treatment of breast cancer. Also, XS-2 was found to be potentially effective against triple-negative breast cancer (TNBC) in vitro during the investigation. We evaluated the in vitro inhibitory effect of XS-2 on 10 cancer cell lines by MTT and 6 kinases to investigated its in vivo antitumor activity in MCF-7 xenograft tumor-bearing BALB/c nude mice. In addition, the in vitro/in vivo toxicity to mice was also assessed by hemolytic toxicity, H&E staining and blood biochemical analysis. In order to investigate the antitumor mechanism of XS-2, a series of experiments were carried out in vitro/in vivo animal model and molecular biological levels such as the cell cycle and the apoptosis assay, real-time PCR, western blot, docking and molecular simulations analysis, etc. What's more, wound healing assay, Transwell and Western Blot were applied to explore the ability of XS-2 to inhibit the cell invasion and migration. The results showed that XS-2 exhibited strong antitumor activity both in vitro and in vivo. The inhibitory activities of XS-2 on ten cancer cell lines were ranging from 1.07 ± 0.11 to 0.002 ± 0.001 µM, which were 1565 times better than that of the lead compound GDC-0941, inhibitory activities against PI3Kα and mTOR kinases were 291.0 and 60.8 nM, respectively. Notably, XS-2 not only showed significant in vivo antitumor activity and low toxicity, with the tumor inhibition rate of 57.0 %, but also exhibited strong inhibitory in the expression of related proteins of PI3K pathway in tumor tissues. In addition, XS-2 significantly inhibited breast cancer MCF-7 and MDA-MB-231 cells in a concentration- and time-dependent manner, and inhibited the migration and invasion ability of MDA-MB-231 and MCF-7 cells. More than that, XS-2 could inhibit the increase of the expression levels of N-cadherin and vimentin upregulated by EGF and reversed the E-cadherin expression down regulated by EGF, resulting in inhibiting EMT in MCF-7 and MDA-MB-231 cells. The results showed that XS-2 was expected to be successfully developed as a high-efficiency and low-toxicity breast cancer therapeutic drug with the potential to inhibit the invasion and migration of TNBC. This provides a new research idea for the treatment of TNBC, which is of great significance.

A Water-Soluble Antimony-Rich Polyoxometalate with Broad-Spectrum Antitumor Activities.

Herein, a giant Sb-rich polyoxometalate (POM) {Sb21 Tb7 W56 } is reported, which contains the largest number of Sb atoms in a POM so far. The Sb-rich POM has many interesting structural features and is a rare example of a soluble and water-stable giant POM. Biomedical studies indicate that the Sb-rich POM exhibits broad-spectrum antitumor activity against various cancer cell lines by reactivating the P53-dependent apoptotic processes and disrupting the mitochondrial membrane. In addition, this Sb-rich POM was capable of suppressing the growth and metastasis of a breast cancer in vivo. This work demonstrates that Sb-rich POMs are promising candidates for the development of new anticancer drugs.

High-affinity SOAT1 ligands remodeled cholesterol metabolism program to inhibit tumor growth.

BACKGROUND: Although cholesterol metabolism is a common pathway for the development of antitumor drugs, there are no specific targets and drugs for clinical use. Here, based on our previous study of sterol O-acyltransferase 1 (SOAT1) in hepatocelluar carcinoma, we sought to screen an effective targeted drug for precise treatment of hepatocelluar carcinoma and, from the perspective of cholesterol metabolism, clarify the relationship between cholesterol regulation and tumorigenesis and development. METHODS: In this study, we developed a virtual screening integrated affinity screening technology for target protein drug screening. A series of in vitro and in vivo experiments were used for drug activity verification. Multi-omics analysis and flow cytometry analysis were used to explore antitumor mechanisms. Comparative analysis of proteome and transcriptome combined with survival follow-up information of patients reveals the clinical therapeutic potential of screened drugs. RESULTS: We screened three compounds, nilotinib, ABT-737, and evacetrapib, that exhibited optimal binding with SOAT1. In particular, nilotinib displayed a high affinity for SOAT1 protein and significantly inhibited tumor activity both in vitro and in vivo. Multi-omics analysis and flow cytometry analysis indicated that SOAT1-targeting compounds reprogrammed the cholesterol metabolism in tumors and enhanced CD8+ T cells and neutrophils to suppress tumor growth. CONCLUSIONS: Taken together, we reported several high-affinity SOAT1 ligands and demonstrated their clinical potential in the precision therapy of liver cancer, and also reveal the potential antitumor mechanism of SOAT1-targeting compounds.

Immune-Cell-Derived Exosomes for Cancer Therapy.

Exosomes are a type of extracellular vesicles secreted by cells in normal or pathological conditions for cell-cell communication. With immunomodulatory characteristics and potential therapeutic properties, immune-cell-derived exosomes play an important role in cancer therapy. They express various antigens on their surface, which can be employed for antigen presentation, immunological activation, and metabolic regulation, leading to the killing of cancerous cells. In addition, immune-cell-derived exosomes have received extensive attention as a drug delivery platform in effective antitumor therapy due to their excellent biocompatibility, low immunogenicity, and high loading capacity. In this review, the biological and therapeutic characteristics of immune-cell-derived exosomes are comprehensively outlined. The antitumor mechanism of exosomes secreted by immune cells, including macrophages, dendritic cells, T cells, B cells, and natural killer cells, are systematically summarized. Moreover, the applications of immune-cell-derived exosomes as nanocarriers to transport antitumor agents (chemotherapeutic drugs, genes, proteins, etc.) are discussed. More importantly, the existing challenges of immune-cell-derived exosomes are pointed out, and their antitumor potentials are also discussed.

Pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives as RAF-MEK-ERK pathway signaling pathway blockers: Synthesis, cytotoxic activity, mechanistic investigation and structure-activity relationships.

The constitutive activation of ERK1/2 (RAF-MEK-ERK) signaling pathway has been widely observed in many types of tumors, and the blockade of ERK1/2 signaling pathway has been proved to reduce tumor growth. Therefore, ERK1/2 signaling pathway has become an interesting therapeutic target for cancer therapy. Despite the successful development of BRAF and MEK inhibitors in clinic treatment, resistance often appears to re-enhance ERK1/2 signaling. Here we report the design, synthesis, biological activity of a series of novel pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives based on compound 1. Among them, the target compound N-(3-chlorophenyl)-2-((1,3-dimethyl-7-(4-methylpiperazin-1-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin-5-yl)amino)acetamide (14m) exhibited excellent antiproliferative activity towards MCF-7, A375, SK-MEL-2 and SK-HEP-1 cells, with low cytotoxicity in C28/I2 cells. Tumor spheroid assay demonstrated the superior potency of 14m in inhibiting the growth of SK-HEP-1 spheroidal models. The mechanism of 14m to induce cancer cell death was shown to suppress cell migrations, induce cell apoptosis, decrease the levels of phosphorylated ERK and MEK in a dose-dependent manner and increase ROS production.

2-Deoxy-D-glucose increases the sensitivity of glioblastoma cells to BCNU through the regulation of glycolysis, ROS and ERS pathways: In vitro and in vivo validation.

Chloroethylnitrosoureas (CENUs) exert antitumor activity via producing dG-dC interstrand crosslinks (ICLs). However, tumor resistance make it necessary to find novel strategies to improve the therapeutic effect of CENUs. 2-Deoxy-D-glucose (2-DG) is a well-known glycolytic inhibitor, which can reprogram tumor energy metabolism closely related to tumor resistance. Here, we investigated the chemosensitization effect of 2-DG on l,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) against glioblastoma cells and the underlying mechanisms. We found that 2-DG significantly increased the inhibitory effects of BCNU on tumor cells compared with BCNU alone, while 2-DG showed no obvious enhancing effect on the BCNU-induced cytotoxicity for normal HaCaT and HA1800 cells. Proliferation, migration and invasion determinations presented the same trend as survival on tumor cells. 2-DG plus BCNU increased the energy deficiency through a more effective inhibition of glycolytic pathway. Notably, the combination of 2-DG and BCNU aggravated oxidative stress in glioblastoma cells, along with a significant decrease in glutathione (GSH) levels, and an increase in intracellular reactive oxygen species (ROS). Subsequently, we demonstrated that the combination treatment led to increased apoptosis via activating mitochondria and endoplasmic reticulum stress (ERS) related apoptosis pathways. Finally, we found that the dG-dC level was significantly increased after 2-DG pretreatment compared to BCNU alone by HPLC-ESI-MS/MS analysis. Finally, in vivo, 2-DG plus BCNU significantly suppressed tumor growth with lower side effects compared with BCNU alone in tumor-bearing mice. In summary, we proposed that 2-DG may have potential to increase the sensitivity of glioblastoma cells to BCNU by regulating glycolysis, ROS and ERS pathways in clinical setting.

Current Perspective of Traditional Chinese Medicines and Active Ingredients in the Therapy of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading lethal tumors worldwide, and the treatment remains a great medical challenge. Surgery and chemotherapy are current standard curative methods for patients with HCC, but the prognosis is still dismal. Based on unique medical theories and rich practical experience, traditional Chinese medicine (TCM) has been broadly employed to effectively treat HCC for a long history. Recently, systematic clinical trials have been well designed to study the efficacy of TCMs in the treatment of HCC, and the underlying antitumor mechanisms were also deeply explored. Here, we reviewed the published clinical evaluation of some commonly used TCMs in the treatment of HCC, and the related anti-HCC mechanisms through in vitro and in vivo study, promoting the modernization of TCM study in oncology for achieving a substantial reduction of HCC burden in the future.

{BiW8 O30 } Exerts Antitumor Effect by Triggering Pyroptosis and Upregulating Reactive Oxygen Species.

We successfully synthesized {BiW8 }, a 10-nuclear heteroatom cluster modified {BiW8 O30 }. At 24 h post-incubation, the IC50 values of {BiW8 } against HUVEC, MG63, RD, Hep3B, HepG2, and MCF7 cells were 895.8, 127.3, 344.3, 455.0, 781.3, and 206.3 µM, respectively. The IC50 value of {BiW8 } on the MG63 cells was more than 2-fold lower than that of the other raw materials. Through morphological and functional features, we demonstrated pyroptosis as a newly identified mechanism of cell death induced by {BiW8 }. {BiW8 } increased 2-fold reactive oxygen species (ROS) levels in MG63 cells at 24 h post-incubation. Compared with 0 h, the glutathione (GSH) content decreased by 59, 65, 75, 94, and 97 % at 6, 12, 24, 36 and 48 h post-incubation, respectively. Furthermore, multiple antitumor mechanisms of {BiW8 } were identified via transcriptome analysis and chemical simulation, including activation of pyroptosis, suppression of GSH generation, depletion of GSH, and inhibition of DNA repair.

Purification of a novel protein with cytotoxicity against non-small-cell lung cancer cells from Boletus bicolor.

A novel protein (D1 component) was purified from Boletus bicolor by ion-exchange chromatography and gel chromatography on a HiTrap™ Q HP column, a diethylaminoethanol cellulose-52 column, and a Sephadex G75 column, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the D1 component was a single protein band with a molecular weight of about 40 kDa. The sulforhodamine B assay showed that at concentrations as low as 25-75 µg/ml, protein D1 significantly inhibited the proliferation of human lung adenocarcinoma cell lines (A549 and H1299 cells) and had little effect on human normal kidney cells (HEK293 cells). After labeling protein D1, it was found that D1 could enter the cytoplasm of tumor cells and colocated with lysosomes. Flow cytometry results demonstrated that protein D1 induced apoptosis and G1 phase arrest of the cell cycle in A549 and H1299 cells. The Western blot analysis results showed that the expression of apoptosis and cell cycle-related proteins of cleaved caspase-3, cytochrome c, Bax, P16, and P21 was significantly upregulated, whereas the expression of Bcl-2, CDK4, cyclin D, p-Rb, and E2F was significantly downregulated after treatment with protein D1. Therefore, D1 exhibits potential to be developed into an antitumor agent.

Rubioncolin C, a natural naphthohydroquinone dimer isolated from Rubia yunnanensis, inhibits the proliferation and metastasis by inducing ROS-mediated apoptotic and autophagic cell death in triple-negative breast cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Rubia yunnanensis Diels is a traditional Chinese medicine that has diverse pharmacological activities, including antituberculosis, antirheumatism and anticancers. Rubioncolin C (RC), a natural naphthohydroquinone dimer isolated from the roots and rhizomes of R. yunnanensis Diels, has shown potent antitumor activity. However, the antitumor activity and its potential mechanism of RC in triple-negative breast cancer (TNBC) cell lines remained unclear. AIM OF THE STUDY: This study was aim to investigate the anti-proliferation and anti-metastasis activity as well as the potential mechanism of RC on triple-negative breast cancer cells in vitro and in vivo. MATERIALS AND METHODS: The sulforhodamine B assay, colony formation assay and cell cycle analysis were used to determine the anti-proliferative activity of RC on TNBC. The anti-metastatic activity in vitro of RC was detected through the scratch wound assay, cell migration and invasion assays and gelatin zymography. The flow cytometry, JC-1, GFP-LC3B plasmid transfection, MDC, Lysotracker red and Carboxy-H2DCFDA, DHE, and MitoSOX™ Red staining were performed to investigate the effect of RC on apoptosis, autophagy and ROS level. The apoptosis inhibitor, autophagy inhibitors and ROS inhibitors were used to further verify the antitumor mechanism of RC. The protein levels related with cell cycle, apoptosis, and autophagy were examined with western blotting. In addition, the anti-tumor activity of RC in vivo was assessed in an experimental metastatic model. RESULTS: In the present study, RC suppressed the proliferation of TNBC cells in a time- and dose-dependent manner via regulating cell cycle. Further experiments showed that RC inhibited the migration and invasion of TNBC cells by downregulating MMPs and inhibiting EMT. Moreover, we demonstrated that RC induced obviously apoptotic and autophagic cell death, activated MAPK signaling pathway and inhibited mTOR/Akt/p70S6K and NF-κB signaling pathways. Furthermore, the excessive ROS was produced after treatment with RC. The antioxygen NAC and GSH could rescue the cell viability and reestablish the ability of cell metastasis, and inhibit the RC-induced apoptosis and autophagy. In a mice lung metastasis model of breast cancer, RC inhibited lung metastasis, and induced autophagy and apoptosis. CONCLUSION: These findings clarified the antitumor mechanism of RC on TNBC cell lines and suggested that RC is a key active ingredient for the cancer treatment of R. yunnanensis, which would help RC develop as a new potential chemotherapeutic agent for TNBC treatment.

Recent advances in polysaccharides from Lentinus edodes (Berk.): Isolation, structures and bioactivities.

Lentinus edodes, an important edible mushroom cultivated in East Asia for thousands of years, has been widely used as food and medicinal ingredient worldwide. Modern phytochemistry studies have demonstrated that L. edodes is very rich in bioactive polysaccharides, especially the ß-glucans. Over the past two decades, the isolation, chemical properties, and bioactivities of polysaccharides from fruiting bodies, mycelium and fermentation broth of L. edodes have been drawing much attention from scholars around the world. It has been demonstrated that L. edodes polysaccharides possess various remarkable biological activities, including anti-oxidant, anti-tumor, anti-aging, anti-inflammation, immunomodulatory, antiviral, and hepatoprotection effects. This review summarizes the recent development of polysaccharides from L. edodes including the isolation methods, structural features, bioactivities and mechanisms, and their structure-activity relationship, which can provide useful research underpinnings and update information for their further application as therapeutic agents and functional foods.

Transcriptome analysis reveals possible antitumor mechanism of Chlorella exopolysaccharide.

Microalgae, one of the most important classes of biomass producers, can produce exopolysaccharides similar to bacteria. The exopolysaccharide from Chlorella (CEPS) displays remarkable anticancer activity the mechanism of which remains to be elucidated. In this study, we analyzed the inhibitory effect of CEPS on the growth of HeLa cells. The results showed that CEPS inhibited the proliferation, decreased the viability, and changed the morphology of HeLa cells. Transcriptome analysis showed that 1894 genes were differentially expressed in the CEPS-treated group compared with the control group, including 1076 genes that were upregulated and 818 genes that were downregulated. The results of gene function enrichment analysis showed that the differentially expressed genes (DEGs) were significantly enriched in apoptosis and tumor-related biological processes and participated in several cancer and apoptosisrelated signaling pathways, including the MAPK signaling pathway, TNF signaling pathway, and the PI3K-Akt signaling pathway. The protein-protein interaction network identified 13 DEGs including PTPN11, RSAD2, ISG15, IFIT1, MX2, IFIT2, OASL, OAS1, JUN, OAS2, XAF1, ISG20, and IRF9 as hub genes. Our results suggest that CEPS is a promising therapeutic drug for the follow-up interventional therapy of cancer.

RA-XII, a bicyclic hexapeptidic glucoside isolated from Rubia yunnanensis Diels, exerts antitumor activity by inhibiting protective autophagy and activating Akt-mTOR pathway in colorectal cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Rubia yunnanensis Diels (Chinese name 'Xiao-Hong-Shen'), a traditional Chinese medicine native to Yunnan province (China), have a long history of use for treating several diseases, such as tuberculosis, rheumatism and cancers. A bicyclic hexapeptidic glucoside named RA-XII was isolated from R. yunnanensis, which has been reported to exert anti-inflammatory and antitumor activities. AIM OF THE STUDY: This study was designed to investigate the antitumor activity and potential mechanism of RA-XII on colorectal cancer (CRC) cell lines. MATERIALS AND METHODS: Sulforhodamine B assay, clonogenic assay and cell cycle analysis were conducted to assess the anti-proliferative activity of RA-XII on CRC cells. GFP-LC3B plasmid transfection, MDC and AO staining assays, cathepsin activity assay, and siRNAs against several genes were used to investigate the effect of RA-XII on autophagy. Western blotting was used to examine the expression levels of proteins associated with cell cycle arrest, apoptosis and autophagy. Human CRC xenograft-bearing BALB/c nude mice were used to evaluate the antitumor effect of RA-XII in vivo. RESULTS: RA-XII showed favorable antineoplastic activity in SW620 and HT29 cells in vitro and in vivo. RA-XII did not induce apoptosis indicated by no obvious changes on mitochondrial membrane potential and apoptosis-related marker proteins in SW620 or HT29 cells. Treatment of RA-XII inhibited the formation of autophagosomes, which is implied by the GFP-LC3 fluorescent dots, MDC-stained autophagic vesicles and LC3 protein expression. It was indicated that RA-XII suppressed autophagy by regulating several signaling pathways including mTOR and NF-κB pathways. Pharmacological or genetic inhibition of autophagy could enhance the cytotoxicity of RA-XII while autophagy inducer could rescue RA-XII-induced cell death. Besides, RA-XII could increase the susceptibility of CRC cells to bortezomib. CONCLUSION: Our study demonstrated that RA-XII exerted antitumor activity independent of apoptosis, and suppressed protective autophagy by regulating mTOR and NF-κB pathways in SW620 and HT29 cell lines, which suggested that RA-XII is a key active ingredient for the cancer treatment of Rubia yunnanensis and possesses a promising prospect as an autophagy inhibitor for CRC therapy.

Ethyl Acetate Extract of Selaginella doederleinii Hieron Induces Cell Autophagic Death and Apoptosis in Colorectal Cancer via PI3K-Akt-mTOR and AMPKα-Signaling Pathways.

Colorectal cancer is one type of cancer with high incidence rate and high mortality worldwide. Thus, developing new chemotherapeutic drugs is important. The Selaginella doederleinii Hieron ethyl acetate (SDEA) extract showed good anti-colon cancer effect in vitro and in vivo, but its mechanism is unclear. This study aimed to further reveal the anti-colon cancer effect of SDEA and its possible mechanism. The effects on cell viability, apoptosis, autophagy, and cell cycle in colorectal cells (HT29 and HCT116) were studied using MTT assay, fluorescence microscopy, transmission electron microscopy, and flow cytometry. The mechanisms were further studied using cell transfection, Western blot, and real-time quantitative polymerase chain reaction assay. The effect of xenotransplantation in vivo was observed using immunohistochemistry. Results showed that SDEA inhibited cell proliferation and induced cell morphological changes, cell cycle arrest, autophagy, and apoptosis. It also induced loss of mitochondrial membrane potential, increased the autophagic flux, raised the ratio of Bax/Bcl-2, activated caspases, and inhibited PI3K-Akt-mTOR signaling pathways. Furthermore, SDEA inhibited the growth of xenograft tumors in a dose-dependent manner. Immunohistochemistry analysis confirmed the alteration of autophagy- and apoptosis-related proteins and immunohistochemical microvascular density in xenografts, which were consistent with the results in vitro. Therefore, SDEA is important for developing candidate drugs against colorectal cancers.